This invention relates generally to an aircraft control system and more specifically concerns an aircraft pitch attitude stabilization system that utilizes one or more engine pressure ratio signals to cancel pitching moments due to changes in thrust.
In the unaccelerated trimmed flight of an aircraft, all forces and moments are balanced about the aircraft's center of gravity. In an aircraft in which the engine thrust vector is offset from the center of gravity of the aircraft, the engine thrust contributes to the net pitching moment. In the past the pitching moment due to engine thrust has been counteracted by detecting the motion due to the moment and then generating a pitch control deflection that creates an opposing pitching moment. The disadvantage with these prior art systems is that there is always some unwanted motion due to engine thrust changes.
It is the primary object of this invention to provide means for automatically generating a stabilization signal which causes a pitch control deflection to counteract the pitching moment due to an engine thrust change on an aircraft.
Another object of this invention is to providing a means for anticipating the pitching moment of an aircraft due to engine thrust change and to generate a pitch stabilization signal to counteract the pitching moment before there is any unwanted motion due to engine thrust change.
Other objects and advantages of this invention will become apparent hereinafter and in the drawings.